Landfill Mining Brought To The Surface

When the word "mining" comes to mind, it is usually paired with a commodity like gold, silver, or
coal. Trash and recycling probably do not make your short list of popular items to be mined, but Landfill Mining and Reclamation (LFMR) has become a more popular process. It was first described and documented in 1953 but the process was not applied again until the 1980s. Several developments and process upgrades occurred between these dates making LFMR a more efficient and effective technological breakthrough.

Landfill mining serves a few specific purposes, mainly, reclamation of a particular piece of land, recovery of recyclable materials that have been discarded, soil recovery (which is generally now rich in nitrogen, phosphorus, and potassium). Soil amendments such as these have been primarily used in citrus groves. The aeration of the landfill soil is a secondary benefit regarding the landfill's future use.

Although this cutting edge design and ingenuity has been attempted overseas, it has been documented fewer times in the United States. Florida, New Hampshire, New York, Pennsylvania, and Connecticut are among the states having implemented this up-and-coming environmentally friendly process.

The stability of organic wastes is essential to LFMR and must be measured before the mining process begins. Health and safety concerns are imminent if mining insufficiently decomposed waste is attempted. For this reason, only completed landfills, or landfills that have been properly managed and closed, should be candidates for landfill mining.

If mining a particular landfill is especially important before it has been properly closed, a process of Accelerated Decomposition may be called into effect, therefore speeding up the natural decomposition processes so this process can occur sooner than planned.

"The aftercare period for a closed landfill is limited, and landfills also occupy enormous amounts of land. The next step in waste management policy, therefore, consisted of combining landfill practices with a Waste to Energy (WtE) approach." Waste to Energy will be discussed at length in a future article.

Waste contains many resources with high value, the most notable of which are non-ferrous metals such as aluminum cans and scrap metal. The concentration of aluminum in many landfills is higher than the concentration of aluminum in bauxite from which the metal is derived.

Mining construction landfill sites is the easiest form of landfill mining. Construction landfills contain three basic components; wood, scrap metal, and gypsum (drywall), along with a small amount of other construction materials. The wood that is collected can be used as fuel source in coal burning power plants and the scrap metal reprocessed.

The mining of municipal landfills is more complicated and has to be based on the expected content of the landfill since the actual content and reclamation can only be speculated.

Landfill mining is also practiced in countries where land is not available for new landfill sites. In this instance, landfill space can be reclaimed by the extraction of biodegradable waste and other substances then refilled with wastes requiring disposal.

All in all, landfill mining can be an invaluable tool when reclaiming land previously used as a dump site, as long as it is done properly leaving the land healthier and in better shape than when the mining began.

wikipedia.com
waste-management-world.com
enviroalternatives.com